Table 1.

Composition and analyzed values of experimental diets¹

Item2	Phase 1
Phytase:	0 FTU		2,000 FTU
Ca and P levels:	Adequate	Deficient	Adequate	Deficient	Phase 2	Phase 3
Ingredient, %
Ground corn	42.42	45.91	43.85	46.80	42.01	51.55
Soybean meal, 48% crude protein	22.00	22.00	22.00	22.00	28.00	32.00
Lactose	15.00	15.00	15.00	15.00	15.00	10.00
Soy protein concentrate	8.00	8.00	8.00	8.00	8.00	-
Enzyme-treated soybean meal	2.50	2.50	2.50	2.50	-	-
Spray-dried plasma protein	3.00	3.00	3.00	3.00	-	-
Soybean oil	3.00	1.26	2.29	0.82	3.00	3.00
Ground limestone	1.28	0.72	1.13	0.37	1.19	1.11
Monocalcium phosphate	1.29	0.13	0.69	-	1.27	0.94
l-Lys HCl	0.26	0.25	0.26	0.25	0.31	0.38
dl-Met	0.17	0.16	0.16	0.15	0.17	0.15
l-Thr	0.08	0.07	0.08	0.07	0.10	0.12
Sodium chloride	0.85	0.85	0.85	0.85	0.80	0.60
Vitamin-mineral premix3	0.15	0.15	0.15	0.15	0.15	0.15
Phytase concentrate4	-	-	0.04	0.04	-	-
Total	100.00	100.00	100.00	100.00	100.00	100.00
Calculated values5, %
Total Ca	0.83	0.42	0.67	0.26	0.80	0.70
Total P	0.66	0.43	0.54	0.40	0.64	0.56
STTD P	0.43	0.22	0.32	0.20	0.40	0.33
Analyzed values
Gross energy, kcal/kg	3,990	3,947	3,982	3,966	3,973	3,968
Dry matter, %	89.41	88.84	89.46	89.23	88.75	88.62
Ash, %	6.33	4.63	5.80	4.54	5.63	5.27
Crude protein, %	21.50	22.21	21.87	22.58	20.34	18.58
AEE, %	4.81	2.88	4.20	2.61	4.48	4.35
Amino acids, %
Arg	1.49	1.42	1.50	1.39	1.38	1.30
His	0.59	0.58	0.60	0.58	0.54	0.50
Ile	1.02	0.98	1.03	0.98	0.95	0.89
Leu	1.87	1.83	1.90	1.83	1.72	1.58
Lys	1.60	1.53	1.60	1.63	1.50	1.40
Met	0.51	0.44	0.48	0.42	0.43	0.40
Phe	1.13	1.09	1.15	1.09	1.04	0.97
Thr	1.00	0.94	1.03	0.97	0.95	0.91
Trp	0.29	0.28	0.28	0.28	0.27	0.25
Val	1.18	1.14	1.19	1.13	1.06	0.96
Ca, %	0.91	0.47	0.65	0.22	0.90	0.79
P, %	0.64	0.46	0.56	0.38	0.69	0.61
Phytate6, %	0.90	0.93	0.91	0.93	0.95	0.93
Phytate bound-P7, %	0.25	0.26	0.26	0.26	0.27	0.26
Non-phytate P8, %	0.39	0.20	0.30	0.12	0.42	0.35
Phytase activity, FTU/kg	< 70	< 70	1,400	1,400	< 70	< 70

¹Phase 1, phase 2, and phase 3 diets were formulated to have the following quantities of net energy (NE; kcal/kg) and amino acids (expressed as standardized ileal digestible; %): NE, 2,518, 2,496, and 2,498; Lys, 1.41, 1.35, and 1.23; Met, 0.46, 0.45, and 0.41; Thr, 0.83, 0.80, and 0.74; Trp, 0.26, 0.24, and 0.22, respectively.

²AEE = acid hydrolyzed ether extract; FTU = phytase units per kilogram of feed; STTD = standardize total tract digestible.

³The vitamin-micromineral premix provided the following quantities of vitamins and micro minerals per kg of complete diet: vitamin A as retinyl acetate, 11,150 IU; vitamin D₃ as cholecalciferol, 2,210 IU; vitamin E as dl-alpha tocopheryl acetate, 66 IU; vitamin K as menadione dimethylprimidinol bisulfite, 1.42 mg; thiamin as thiamine mononitrate, 1.10 mg; riboflavin, 6.59 mg; pyridoxine as pyridoxine hydrochloride, 1.00 mg; vitamin B₁₂, 0.03 mg; d-pantothenic acid as d-calcium pantothenate, 23.6 mg; niacin, 44.1 mg; folic acid, 1.59 mg; biotin, 0.44 mg; Cu, 20 mg as copper sulfate; Fe, 125 mg as ironsulfate; I, 1.26mg as ethylenediamine dihydriodide; Mn, 60.2 mg as manganous sulfate; Se, 0.30 mg as sodium selenite and selenium yeast; and Zn, 125.1 mg as zinc sulfate.

⁴The phytase concentrate contained 5,000 units of phytase/g (Quantum Blue, AB Vista, Marlborough, UK).

⁵Phytase was assumed to release 0.16% total Ca and 0.11% STTD P.

⁶Phytate values in the diets were calculated from analyzed phytate in the ingredients.

⁷Phytate-bound P was calculated by multiplying the phytate by 0.282 (Tran and Sauvant, 2004).

⁸Non-phytate P was calculated as the difference between total P and phytate-bound P.